World grid of cosmic ray vertical cut-off rigidity for the last decade

Cosmic ray cut-off rigidity tables and maps over the world concerning the epochs 2010, 2015 and the current one 2020 have been constructed. These maps display the effective cut-off rigidity in every five degrees in latitude and in longitude at the altitude of 20 km above the surface of the international reference ellipsoid. The values of the geomagnetic cut-off rigidity were calculated in every 5° in latitude and in every 15° in longitude applying the well-known method of particle trajectory calculations resulted from the theory of the particle motion in the Earth's magnetic field. The applied software employed the 12th Generation of the International Geomagnetic Reference Field (IGRF 12) and trajectories were calculated at 0.01 GV intervals in order to determine the vertical cut-off rigidity for each location. Beyond the use of the calculated cut-off rigidity values as a basic reference of charged particle access to different geographical locations during quiet and/or more intense geomagnetic periods, these results can be used for a long- term forecasting of the geomagnetic conditions variations.     

氢/氧火箭发动机试验自动紧急关机程序设计

在氢/氧火箭发动机试验过程中,对发动机关键参数进行监测,及时发现异常或故障趋势,并快速实施自动紧急关机是非常重要的.本文在Pacific 6000数据采集控制系统的基础上,使用Visual C++开发环境对其自带的采集软件PI660进行二次开发,实现高精度自动紧急关机判读功能.在紧急关机程序设计中,定时器的精度直接影响判读的准确性,通过对几种定时器精度的测试和分析,选取“多媒体定时器”用于自动紧急关机程序,并结合Pacif-ic 6000数据采集控制系统的特性,综合分析了自动紧急关机程序的响应时间及可靠性.     

进气压力畸变试验中面平均紊流度的计算

为研究航空发动机进气压力畸变试验中数据处理方法对面平均紊流度计算结果的影响,通过分析涡扇发动机进气压力畸变试验数据,得到了不同取样时间及不同滤波截止频率对面平均紊流度计算的影响结果。分析表明,只有合理选择取样时间及滤波截止频率,才能保证所计算面平均紊流度的准确性。本研究为进气压力畸变试验中面平均紊流度的计算提供了一种参考方法。     

复合材料纤维铺放路径规划与丝数求解

 提出了一种复合材料纤维铺放路径的生成算法。首先探讨了铺放方向的确定,基于由芯模形心线得到的铺放参考线,针对沿0°,45°,90°这3种铺放情况,设计了具体的铺放路径生成算法。在此基础上,建立了纤维丝数与铺放路径间的对应关系,基于铺放路径的等距离线,提出并实现了一种纤维裁剪算法,使得复合材料纤维较为均匀地铺放在芯模表面。基于CATIA CAA,开发了相应软件模块。通过铺放过程的模拟,对本文算法进行了验证。